Tailored Silica Nanoparticles Surface to Increase Drug Load and Enhance Bactericidal Response

Abstract

Nanoparticles' surface properties can be used as triggers to regulate or even enhance biological response and generate tailored structures to substitute conventional antibiotics. Here, silica nanoparticles surface was duly tuned in order to increase the water-insoluble drug load (curcumin) and improve the antibacterial activity. Our main motivation was based on the electrostatic attraction between the positively charged amino groups and the negatively charged curcumin and/or bacteria membrane. In addition, the variation of amino grafting amount on silica nanoparticles indicated that the grafting increase was directly related to the extent of drug entrapped into the nanoparticles as well as to the bactericidal activity. The combination of amino-functionalized silica nanoparticles associated with the presence of curcumin allowed to produce a dual bactericidal system that shows promising perspective for its use in biomedical applications.Keywords: amino-functionalized silica nanoparticles, curcumin, bactericidal activity, Escherichia coli IntroductionPathogenic microorganisms have proved to develop resistance to currently available antibiotics becoming a worldwide concern.1-5 Thus, it is necessary to find new systems or drugs presenting alternative mechanisms of action to substitute the existing commercial antibiotics.Nanoparticles are promising materials for therapeutic applications since they possess unique physical and chemical properties. [6][7][8][9] Thus, silica-based nanoparticles have been widely investigated and used in different fields, including materials science and biomedicine, due to their stability, high hydrophilic surface, biocompatibility and easy surface functionalization. [10][11][12][13] In particular, mesoporous silica nanoparticles are potential candidates as drug carriers since they provide the possibility of encapsulating and delivering large quantities of drugs due to large surface areas and pore volumes. [14][15][16][17][18][19][20] Using the well-known silane chemistry, silica nanoparticles have been functionalized with a variety of different functional groups such as carboxyl, 21 vinyl, 22 amino, 23 mercapto 24 and epoxy. 25 The surface functionalization with organic functional groups allows increasing the storage capacity of drugs or biomolecules within the silica pores. 21,[25][26][27][28] Moreover, the chemical surface modification of the nanoparticles is an important tool to control the interaction of nanoparticles with biological systems while reducing toxicity and increasing the therapeutic effects. [29][30][31][32] Typical surface modification methods via covalent bonds are (i) the co-condensation (one-pot synthesis method); (ii) the postsynthetic grafting (PSG) and (iii) the use of bissilylated organic precursors that generate periodic mesoporous organosilicas (PMOs). [33][34][35] The PSG involves modification of silica after the synthesis. In this method, it is possible to restrict the functionalization of surface-accessible silanol groups both within the mesopore network and o...

Mussel-Inspired Magnetic Nanoflowers as an Effective Nanozyme and Antimicrobial Agent for Biosensing and Catalytic Reduction of Organic Dyes

“…Hue et al 53 reported that the interaction among cationic amino groups and anions on the bacterial wall accelerates bacterial death. Similar research by Oliviera et al 54 analyzed the antimicrobial activity of silica nanoparticles functionalized with different amine percentages to measure their ζ-potential and reported that positive surface charge was sufficient for the antimicrobial properties of the nanoparticles. Rokicka-Konieczna et al 55 have done similar studies and Abbaszadegan et al 56 also confirmed the positive effect of nanoparticle surface charge; thereby, our findings are consistent with the previous reports, and the existence of amine groups is the main key to bacterial growth inhibition.…”

Mesoporous Silica and Organosilica Nanoparticles: Physical Chemistry, Biosafety, Delivery Strategies, and Biomedical Applications

“…Mesoporous silica and organosilica nanomaterials have been applied for antimicrobial applications with different approaches. The first approach involved the transportation of antimicrobial molecular or macromolecular agents via MSNs. The incorporation of antimicrobial ionic liquids inside the mesopores of the particles was achieved in high content by Lin and co‐workers by simply using the ionic liquid as a structure‐templating agent for the synthesis of the particles .…”

Aggregation-Induced Emission of Tetraphenylethene-Conjugated Phenanthrene Derivatives and Their Bio-Imaging Applications

“…Briefly, TPEP derivatives were loaded into silica nanoparticles (TPEP-SiO 2 ) according to the modified synthetic procedures [ 24 ]. In 100 mL round bottom flask, a mixture of 1 mL of TEOS, 32 mL of ethanol and 0.26 mL of TPEP derivatives solution in ethanol were added.…”